<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>02 - ol4加载百度离线地图 512 * 512</title>
    <script src="../lib/bd09.js"></script>
    <script src="../lib/ol4/ol4.js"></script>
    <link rel="stylesheet" href="../css/ol4/ol.css">
    <style>
        * {
            margin: 0;
            padding: 0;
        }

        html, body {
            width: 100%;
            height: 100%;
        }

        #map {
            width: auto;
            height: 100%;
        }
    </style>
</head>
<body>
<div id="map"></div>
</body>
<script>
    const projectionBD09 = new ol.proj.Projection({
        code: 'BD:09',
        extent: [-20037726.37, -11708041.66, 20037726.37, 12474104.17],
        units: '',
        axisOrientation: 'neu',
        global: false
    });
    ol.proj.addProjection(projectionBD09);
    ol.proj.addCoordinateTransforms('EPSG:4326', 'BD:09', coordinate => {
        return lngLatToMercator(coordinate);
    }, (coordinate => {
        return mercatorToLngLat(coordinate);
    }));
    console.log(ol.proj.get('BD:09'));
    const tileSize = 512;
    const projectionExtentInBD09 = projectionBD09.getExtent();
    const size = ol.extent.getWidth(projectionExtentInBD09) / tileSize;

    const resolutions = [];
    const maxZoom = 18;
    const minZoom = 0;
    // 计算百度使用的分辨率
    for (let i = minZoom; i <= maxZoom; i++) {
        resolutions[i] = Math.pow(2, maxZoom - i);
    }
    console.log(resolutions);

    const tileGrid = new ol.tilegrid.TileGrid({
        origin: [0, 0],
        resolutions: resolutions,
        extent: projectionExtentInBD09
        // tileSize: [512, 512]
    });

    const baiduSource = new ol.source.TileImage({
        projection: 'BD:09',
        tileGrid: tileGrid,
        tileUrlFunction: (tileCoord) => {
            let [z, x, y] = tileCoord;
            return `http://maponline0.bdimg.com/tile/?qt=vtile&x=${x}&y=${y}&z=${z}&styles=pl&udt=20210407&scaler=2`;
        }
    });
    // 百度地图层
    const baiduMapLayer = new ol.layer.Tile({
        source: baiduSource,
        tilePixelRatio: 2
    });
    // 邢台 - [114.507435,37.074612] ; 北京 - [116.384722, 39.889916]; 南京 - 【118.802997,32.093289】; 杭州 - 120.176703,30.24834
    //
    const centerPoint = [113.35984, 23.127064];

    const circlePoint = ol.proj.transform(centerPoint, 'EPSG:4326', 'BD:09');
    console.log(circlePoint);

    const iconFeature = new ol.Feature({
        geometry: new ol.geom.Point(circlePoint)
    });

    const iconStyle = new ol.style.Style({
        image: new ol.style.Icon(
            /** @type {olx.style.IconOptions} */ ({
                anchor: [10, 26],
                anchorXUnits: 'pixels',
                anchorYUnits: 'pixels',
                src: '../image/position_orange.png'
            })
        )
    });

    iconFeature.setStyle(iconStyle);

    const vectorSource = new ol.source.Vector({
        features: [iconFeature]
    });

    const iconLayer = new ol.layer.Vector({
        source: vectorSource
    });

    const map = new ol.Map({
        layers: [
            baiduMapLayer,
            iconLayer
        ],
        target: 'map',
        view: new ol.View({
            center: ol.proj.transform(centerPoint, 'EPSG:4326', 'BD:09'),
            projection: 'BD:09',
            zoom: 17,
            maxZoom: 18,
            minZoom: 1,
            resolutions
        })
    });
</script>
</html>